Help to develop the most accurate possible load with stuff I have

[Rick2001]

BlC2 load looks pretty dang salty. Any idea on speed?

[quote=Huckleberry75]BlC2 load looks pretty dang salty. Any idea on speed?[/QUOTE


2283 fps on average]

At 40° of temp.

[Rick2001]

Hi all, I think I need help. I just got the Magnetospeed to check the best BL-C2 load I have developed so far and to say that I was surprised to see my ES and SD is an understatement... they are terrible, and the worst thing is that I don't know what caused this inconsistency in my reload process and how to fix it....
Please take a look and let me know what you think...


To reload I usually use once fired brass, Winchester small rifle primers, and a Hornady Lock and load auto charge. I clean, resize the brass with Lee dies, debur/chamfer, wash them in ultrasonic machine and once dry I reload... I think I am pretty much accurate with the powder but there must be something I do wrong.

Thanks

[tdbru]

do you know how repeatable the magnetospeed is? Could the variation be coming from the measuring tool itself? I do not own a magnetospeed so I am not familiar with the tools repeatability. I am not familiar with the HLNL auto charge, I presume each charge was weighed. One thing long range shooters do to reduce the S/D and ES is to anneal the case necks to try and achieve uniform neck tension. I assume all the brass is the same brand and lot? Did you use once fired cases? You said "usually" but are you sure all the cases in this string were once fired? Have you tried varying seating depth? I've not been fond of LEE dies, but that may be just my biases. How fast was the string fired? Was the barrel temperature significantly different from start to finish? Some powders change burn rate speed faster with temperature change than other powders do. Recently many of the powder companies have come out with "temperature insensitive" powders. If I recall, CFE223, BLC2, and most ball powders have higher tempco's than many extruded powders. StaBALL 6.5 is Winchester Powders' latest entry into the temperature insensitive copper fouling inhibited field. I believe the first ball powder I've heard that has the focus. There may be others. Point is BLC2 burn rate changes with temperature, did you try and space out the shots to keep the barrel temp fairly cool?

With the bullet weights you're using, you might consider giving H4895 a try if you can find some. It has a pretty low tempco. And the burn rate isn't too slow for that bullet weight in the 6.5 Grendel. I'm using BENCHMARK with lighter bullets and H4895 with the bullet weights that you are using, mainly, like you, because I happen to have it at the moment.

if you're not shooting very long ranges, the variation in MV will likely not be a big deal. Since you're grouping pretty well at 100 yards, and if you're not shooting past 300 yards, it may not matter that the SD is higher than you would like.

good luck,
-tdbru

[tdbru]

i just went and re-read what you started with -> "mixed brass". try sorting by headstamp, and re-fire the BLC2 test with brass of the same headstamp.
-tdbru